Well if that's your sister-in-law's view, she's already displayed sociopathic tendencies therefore incapable of judging right and wrong. There is no other "view." There's a reason why the powerful in the US are staunchly anti-drug and it all has its traces back to the Opium Wars. Every powerful family in the West dipped their hands into selling opium to the Chinese. Hence why the opium trade in China was the biggest money-making business in the entire world at the time. And that was a one-way trade only. So if opium were just simply a business to make money, why would the very people who profited from it are staunchly against the recreational drug business at home? Opium's primary purpose was to weaken China by turning everyone into drug addicts to make colonization easier.
I totally agree, that is my view too.
And yes, she does displayed sociopathic/psychopathic traits (along with very strong "princess syndrome") so it could just mean she is just trying to assert something completely irrational (and unfamiliar) to assert her "power" in the family (to show she is the authoritative in chinese history).
Seriously, I am not trolling. This is actually what my sister-in-law told me. As I mentioned before she is a mainlander Chinese - her view shocked me and made me question whether if this is the prevalent view in China or if she was taught this way, or
if it is just her.
I am just trying to configure out how she came to such extreme view. BTW, she studied finance (accounting).